a few MS2 wiring questions
 

I purchased a used MS2 assembled by Brain, and I will be installing it shortly. I have read through all of the super important megasquirt threads and its very possible that I have missed a few things.

anyway I was told that this was on a 94 and it will be going in a 95 so there is no issue there, but I have 3 questions

First, there is a pink cut wire that is on pin 2N that says "OEM NB" on the write up on here. what exactly is this?

Next There is a very long red wire that is a thicker gauge coming out of the loom but not in the harness. this looks like a power wire but now I feel like a total noob since I dont know where this goes. I also bought an Innovate LC1 at the same time and am thinking that this could have to do with that.

Last I would like to retain my A/C but it looks as if this is not wired for it. My question is could I in theory just have my fans programed to run all the time, then have my AC button wired strait to the AC compressor relay? so when the button is on the compressor is on?

Here are a few pictures of what I have, Thank you in advance.

-Kevin

https://www.miataturbo.net/attachmen...ine=1367984731

https://www.miataturbo.net/attachmen...ine=1367984731

https://www.miataturbo.net/attachmen...ine=1367984731

It surprises me that the members more expert than me haven't offered anything, so I'll try...

1. 2N goes to the O2 sensor.

2. Do a little detecive work. Open up the MS, set your DMM to buzz on continuity, and figure out where that red wire goes. Documentation is here: Megasquirt MSEXTRA Manual Index Scroll down to find the schematics. Note that pin 23 on the DB37 connector is usually used for the O2 input, but Brain might have done it differently just to fuck with you.

3. Fans and AC ... I can't help you. Search is your friend. I know there are write-ups on diyautotune.com on how to do it with the DIYPNP, which is based on the MS2, but I really don't know how much transfers over..

Thanks man,
AC isnt my biggest concern and ill figure that out.

my next step was just to open up the unit and see what my mystery wire was.

good to know on the O2 sensor. I take it that NB means narrow band then...

https://www.miataturbo.net/attachmen...ine=1368430703

Turns out this wire is the input for the LC-1 as I figured. pin 23.

Now just to check to see if the unit has been wired for A/C

it has.

no clue what the thick red wire is, that wasnt a wire I added. Probably spliced into the red power wire; easy enough to figure that one out.

Whomever owned that MS before you cut the pink o2 input wire to wire the wbo2 directly into the MS and not through the OEM input.

Pin 23 is the wbO2 sensor input correct Brain?

yes